Blowpipe machine



A. M. KELLER BLOWPIPE MACHINE June 15, 1948.

6 Shets-Sheet 1 Filed May 30, 1944 INVENTOR ARTHUR M. 'KELLER BYATTORNEY I I W A. M. KELLER BLOWPIPE MACHINE June 15, 1948.

6 Sheets-Sheet 2 Filed May 50, 1944 INVENTOR ARTHUR M. KELLER ATTORNEYJune 15, 1948. I I KELLER 2,443,251

BLOWPIPE MACHINE Filed May 30, 1944 6 Sheets-Sheet 3 INVENTOR ARTHURM.-KELLER ATTORNEY June 15, M K L ER 2,443,251

BLOWPIPE MACHINE Filed May 30, 1944 e Sheets-Sheet 4 INVENTOR ARTHUR M.KELLER ATTORN Y June 15, A M, K LL R 2,443,251

BLOWPIPE MACHINE Filed May 50, 1944 6 Sheets-Sheet 5 x A Wm MHHHH IINVENT QR ARTHUR M. KELLER ATTORN EY June 48.

ELLE BLOWPIPE MACHINE Filed 30' 1944 6 Sheet s 6 v /771 B 102 Y r v v I1/ Z: w [40 r I I 42 I 12's /27 k NVENTo ARTHUR M. KELLER Patented June15, i943 BLOWPIPE MAcHiNn Arthur M. Keller, Livingston, J .,;assigiiorto The Linde 'AirProductsc mpa y, a corpora tion of Ohio Application May30, 1944, said-st; acacia" 22 Clahns.

This invention relates to blowpip'e machines,

and. more particularly to machines for moving one or more cuttingblowpipes transversely of a workpiece or elongated ferrous metal stockto cut the stock into shorter lengths. v I I In a steel rolling mill,the rolling operation produces elongated bars, billets, or slabs, whichmay be round, rectangular, or other shape in cross section Blowpipemachines heretofore havebeen limited to operate upon only one shape ofbar or,

slab, or have required elaborate adjustment to convert the machine foroperation upon another shape. It is therefore a principal object of thepresent invention to provide a blowpipe machine which will operatesubstantially equally well 'on round, rectangular, or other shapedstock, with little or no adjustment for the transition from one shape tothe other.

One type of prior blowpipemachine comprises a boom adapted to beextended over the stock from a position clear of the stock, and,mechanism on the boom for advancing the blowpipe across the stock duringthe cut. Other objects-of the present invention are to provide, in ablowpipe machine of the boom type,'improved means for locating the boomover the workpiece, for traversing the blowpipe across the stock, andforre tracting the boom and the blowpipe. I

The cutting operation performed by a machine of this type is desirablefor trimming the ends of metal stock, or for cutting the same intolengths;

and to increase the speed and adaptability of pro-v duction, furtherobjects of the invention are to provide a machine which can make aplurality of simultaneous cuts, such as trimming both ends, or makingintermediate length-severing cutsQand which can be adjusted to vary thespacing between such simultaneous cuts. These objects are preferablyaccomplished by providing a plurality of blowpipe mechanisms supportedon the same boom and laterally adjustable with respect to each other,and common means for actuating these mechanisms. i

It is desirable when cutting stock of square or rectangular crosssection to start the cut with the blowpipe held at a trailing angle andto complete the cut with the blowpipe held at a leading angle.

It is also desirable to retract or raise the blow-'- I pipe and itsassociated mechanism clear of the stock at the completion of the cut,regardless of the cross-sectional shape of the stock. Accordingly,further objects of this invention are to provide a blowpipe machinehaving improved mechanism for these purposes, and to provide-commonmeans 'for actuating a plurality of laterally spacedblowpipessimultaneouslyfor these pur- Other objects and features of novelty willbe .,,apparent' as the following description proceeds,

" with reference to the accompanying drawings, in

Which:

, Fig. 1 is a side elevation of a machine according to thevpreferredembodiment ofthe present invention showing the parts inretracted position in '10 "full lines, and in dotted lines in projectedposition in operative relation to the work;

Fig- 2:,isa top plan viewof the machine shown in Fig;- ;1,; i Fig. ,3is, an elevation of the lower portion of the side.- of, themachineopposite from that shown in Fig. 1, with the cover removed to showdetails of control mechanism mounted on the base of the machine;

Fig. 4 is a rear elevation of the machine, cover 2t boxes being removedto show the internal construction; V,

Fig. 5 is a partial front elevation of the machine, showing the blowpipesupporting mech- ;anism;...' l c a V Fig.6 is a rear elevation of. theblowpipe supporting mechanism shown in Fig. 5; I 1

Fig. 7 is an enlarged vertical, cross section taken on the line of Fig-2throughthe blowpipe vg supporting mechanism and showing thetrailing u sH Figs. 8, 9 and lfljareenlarged sections showing variousdetails of themachine. Fig. 8 is taken along the line 8-,-8 ofFig. 2; Fig. 9 is takenalong -the. line 9'9 of Fig. 6; and Fig. 10, is taken along theline|0,-l0ofFig.9;

Fig. 11 is a longitudinal section through the feed beampshowing-the camsfor tilting the blowpipe mechanism; V

Fig. 12 is a planof the mechanismfor shiftin the, cams shown in Fig. 11;and i i Fig.' 13 is, a section taken along line l3l3 o Fig.12, a

In the drawings the workpiece or elongated ;n1eta1 stock is representedby a'steel billet A, of round, rectangular or other cross section, whichmay be supported by and propelled into position by a conveyor. which ,isrepresented by a series of driven rollersjR, or the stock maybepropelled along such rollers into cutting position. 60

base K, which may be abaseplate forming part of a wheeled truck movableon rails into position adjacent't-h stock A onthe conveyor representedby the rollers R. .On the base K, a pair oflinksL are pivotally mounted,the upper ends of which piv- In general the blowpipe machine comprises aotally support a main boom T in position disposed transversely to theconveyor table.

Longitudinally slidable within and extendin through the front end of themain boom T is a fluid pressure piston P 'for causing a swinging.

movement of the main boom T while maintaining it horizontal at alltimes. Thus the main boom T, is moved from the retracted position shownin full lines in Fig. 1, to the parallel position show in dotted lines.The main boomT is swung,for; ward and down upon the stock}; untilstoppedby.

the same, to bring the blowpipe 'B into position for operating upon thebillet A or other stock on the rollers R. The piston P is alsooperablefor; the reverse movement, to swing the main boom T upwards andbackwards to return it to retracted position after the completion ofeach cut,

For. advancing" and returning theblowpipe B I across the metal stock tobe cut, the carriagejor feed beam D is propelled in a forward directionand retractedby means of arack W drivenbyi gearing Gfrom a, motor M.This motor maybe energized for example by a motor generator set, andby'suitable electriccontrolssuch-as a-rheostat, the motor speed can bevaried through a wide range of appropriate oxy-acetylene cut-tingspeeds.

The feed beam D at its frontend carries a sup-- port S which is parallelto the longitudinalaxis of the stock to be cut, and on which one or moreblowpipe units U are transversely adjustably mounted. In the form shown,thecentral unit is permanently installed at the center of the -machine,and the other two are adjustablefor length Each unit comprises a ofstock between cuts. frame F on which is pivoted a-blowpipe supportingand nozzle-projecting trailing arm J, the end of which extendsrearwardfrom such pivotalcon nection. The rear end portion of the arm J isforked to receive a blowpipe B.

The contour of the underside of the trailing arm J is such thatit.mayibe trailed or dragged so as to slide acrossthetop surfaces ofvarious 1 shapes of workpieces as the-'cutprogress'es, and will maintainproper blowpipe relationship with the surfaces of these shapes. Thetrailing arm'J. at all times prevents mechanical contact between i thestock and the nozzle of the blowpipe and being free to oscillate througha limited movement, in so doing proportionately raises and lowerstheblowpipe B to maintain the-correctrelation be-i im e; T prevent lateraldisplacement pf tween the gas discharge orifices of the nozzle of theblowpipe and the surface of thestock A. This trailing arm J is soconstructedthat in the cut-= ting of round or square bars or slabswithin the capacity of the machinethe change'-over-- from one shape tothe other is very" simple, and does not necessitate anyadjustmentofthe-mechanism of the machine, in most casesentailing onlycutting speed and oxygen pressureadl'ustments. I

At the completion of the'cut, the blowpipes -B are simultaneouslyraised, all gases arevalved off, the large pressure fluid cy-lin'der Praises and pushes back the main boom T, and the feed beam. drive motor Mreverses at its maximum speed; automatically stopping when the feed beamreaches its fully retracted position, the machine then being ready forthenextcutting cycleI j 4 through which extend link-supporting shafts I2, on the outer ends of which are journaled bearings [3 carried by thelower ends of the links L. The upper ends of the links L carry bearingsI4 5 journaled on the ends of shaft I5 in the main boom T.

The links L serve to support the main boom T for parallel motionwithrespect to the bedplate K, because the shafts i5 on the main boom arespaced apart the same distance as the spacing of the shafts [2 on thebedplate, and the links L are of equal efiective length, althoughdifferentlyshaped if desired for clearance purposes,

andsuitably reenforced or transversely framed to p v t side, swa

The fluid pressure cylinder P has a head bracket [6 pivotally mounted onthe bedplate link-supporting shaft-l2 between the bearings for the frontlink. A piston rod I! for the cylinder P isgo pivotally connected by aWrist pin IB to brackets I9 mounted on the rear link L, Fluid underpressure; preferably compressed air is supplied to the cylinder l? bypiping shown in Fig; 3; controlled by a valve 2ilop erated by asolenoidZ I. The com-- 5 5 pressed air system is also; controlled; by a valve-22which is actuated byan arm 23 movable'with the rear link about its shaft[2.

As shown in Figsl and 3, the rear bracket H ha an upwardly extendingpost 25 provided with ,a socket 26 to receive a portion of the rear linkL, the link and socket having registering apertures to receive a 'lockig pin 21, to retain the-boom in retracted position when not in use, andavoid gravityprojection thereof when the fluid pressure supplyi-sfoutoff from the cylinder P- in taking the machineout of operation.

The main boom T comprises ahollow elongated box-like structure shown in'Fign l, formed of a floor plate 30, side plates 3i and 3Z,'and'a topmplate 33." ;Thejside plates have bosses 35 for sup,-

porting the boom supporting shaft it; As shown in Ffig l, thefront endof the: mainboom -T has r bolted thereto a stop bracket 36 for engaging,the top of the workpiece or stock A when themain boom'T is in operativeposition.

As best shown in Fig. 4, thecarriageor feed; beam D -comprises atrough-like structure, having a bottom wall 40 and side walls ll and 42.The" feed beam D is guided for-movement lengthwise of the-main boom T,by verticalt-hrust guide rollers e5 journaled on thesideplates aboveandbelow the bottom, wall 40 and extending inwardly toreceivetherebetween lateral extensions of the; bottom wallto retainthegsame in a horizontal "feed beam D, side thrust guide rollers Mj'arejournaled on the top plate 33 and depend there-.; from to engage theouter surfaces of the side. walls 4| and 42. m e The rack W for'drivingthe feed beam D back and forth within the m-ain boom T, issecured toundersid gc h 'fe d. b m flo i and meshes with a pinion 4'! on a shaft48 journaled1 in a pillow block bearing 4 9 mounted on, the main 5 th mfloqrpl t fifl an p ss n hrou h a f an e. type hearing: 50 in the mainboom, sideplate 3L. T esl v 7. .8 h k d eretoa d vi e...flan e. :5 9qnel=t d by e s eri in 5 .110 asnmcktfi. sel 'mpunt d. on thenu erlen nf.th shaft 48; The-sprocket 4 is driven byfia .chain 55, from a,

respr et'fifi, an idler Sp 'Q.k$ll1' n ipl a.. eis il ke nh chaint t..UThe sprocketsifi is dr ren' b th m tor.Mthrou hreducmngear:i... ing Wmechanism driven byithe drive motor M, limit switches 58 and 59 as shownin Fig. Ziare mounted on the main boom T and are actuated by suitablecams (not shown) which are carried by the feed beam D. The limit'switch58 is actuated only by overtravel of the feed beam in' the forwarddirection, but the limit switch 59 is actuated bythe feed beam Dreaching its fully retracted position at the end of its movement in theopposite or rearward direction. The limit switch 59 may be provided withspare contacts for the connection of electrical interlocks to preventthe running of the conveyor table R when the machine is not in itsretracted position. As a further safety measure a mechanical stop isprovided as shown in Fi 1, which comprises a bracket 60 mounted on themain boom plate 39 and engaging angle brackets GI and 52 attached to theunderside of the feed beam floor as shown in Fig. 4.

The mechanism for supporting the blowpipes is mounted at the front endof the feed beam D, as shown in Fig. '7; The feed beam D terminates atits forward end in a vertical plate 65 which is rigidly secured to theside walls 42 and the bottom wall 49 and preferably integral therewith.The frame F of the central blowpipe unit U is channel shaped in sideelevation, the legs of the channel being bolted to the plate 65 andprovidedwith upper and lower guideways 66 which adjustably receive thelaterally extending support S shown in the form of an I-beam 61.

Each blowpipe unit frame F has a plurality of vertical externalstiffening flanges 68 which are provided with spaced depending bearings69 (Fig. 5) in which is journaled a shaft 10. The front end ofzeachtrailing arm J is provided with .bosses 12 mounted on the outer ends ofthe shaft Ill. The rear end of each trailing arm J is forked to providea pair of laterally spaced lugs 13 which are pivotally connected to theyoke or fork of the blowpipe holder 14, shown in Fig. 6. The pivotalconnection is shown in Figs. 9 and 10, in which the lug I3 carries ascrew 15 having a pointed end, engaging a groove 16 in a pin 17 mountedin a boss on the blowpipe holder yoke 74.

The lower surfaces of the trailing arm J and its lugs I3 are hardsurfaced with a. wear-resisting material such as atungsten-cobalt-chromium alloy, or other material which is highlyresistant to heat, wear and abrasion. These surfaces comprise threeportions which engage the stock at different times during the operation.A curved approach cam surface 18 is adapted to engage the stock ahead ofthe blowpipe during the starting or initial part of the cutting stroke.This is followed by a downward projection or skid 19, substantiallyaligned with the nozzle of the blowpipe B and adapted to engage and rideupon the surface of the stock during the main part of the cuttingstroke. Finally, an upwardly and rearwardly curved receding portion 80is adapted to engage the stock during the final stage of the forwardstroke or cutting operation.

The-yoke I4 is formed at the lower end of a tubular holder 8! whichprovides amounting for the blowpipe B. The blowpipe may be of anydesired construction, the one shown being a conventional tubularjacketed water-cooled type oxyacetylene cutting blowpipe. The tubularholder preferably provides a floating mounting, in which the height ofthe blowpipe B is determined by a sleeve 82 adjustably clamped on theblowpipe and engaging the top of theholdenz.

6 The sleeve 82 is preferably set inpositionby the operator. using agauge while the blowpipe is on the bench before being inserted in thetubular holder BI. I

The yoke 14 also preferablyserves to support structure for providingauxiliary preheating flames if desired, for example to permit flyingstarts on hot steel, the preheat structure as well as the cuttingblowpipe being gauged and protected by the lugs 13. A collar 84 isadjustably mounted on the blowpipe B by means of a cap screw 85projecting through a slotted hole 86 in the yoke 14. The collar 84supports laterally extending curved gas conduits 8'! terminating inpreheating blowpipe tips 88 arranged to direct preheating gas jetsdownwardly and inwardly against the work ahead of the jets discharged bythe cutting nozzle N of the blowpipe B, as shown in Fig. 6. The conduits81 are connected by a pipe 90 to a preheat gas mixer 9I mounted on theblowpipe holder 8 I.

For raising the trailing arm J and the blowpipe mechanism carriedthereby to elevated or retracted position, the trailing arm J is formedwith an integral crank 92 extending upwardly from the central boss 12 atthe front end of the trailing arm J, so as to be pivoted therewith aboutthe shaft 19. As shown in Fig. 5, the upper end of the crank 92 moves ina slot 93 between the pair'of stiifening flanges 68, and carries aroller 94 which is engaged by a cam surface 95 carried by a rocker 96 ona shaft 91 journaled in bearings 98 mounted on the lower flange or theI-beam 61. An adjustable stop 99 on the frame F engages the cam surface95 upon forward movement of the rocker 96 and thereby limits the upwardmovement of the trailin arm J.

To operate this blowpipe elevating mechanism,

the rear side of the rocker 95 is provided with a roller I00, in turnengaged by a pusher rod I 92 slidably mounted in a bushing I03 providedin the plate 55. The head of the pusher rod passes through a suitableaperture in the I-beam 61, and the pusher rod extends rearwardlytherefrom through the bushing I93 and a slide bearing I04 to the rear ofthe feed beam as shown in Fig. 12, where it passes through another slidebearing I05 and is connected to the piston of a fluid pressure cylinderI06 mounted on the feed beam floor 49.

For tilting the blowpipe during the cutting stroke to start the out at atrailing angle and for completing the cut at a leading angle, the upperend of the blowpipe holder 8I has secured thereto a forked blowpipetilting bracket I01. The limbs of this bracket are spaced apart and bothare notched to receive a blowpipe tilting rod I08 secured in the notchesby covers I09 which, as shown in Fig. 2, are spaced apart to givelateral support to the rod I08. Between the limbs of the bracket I01,the rod I 08 is engaged by a hook I I!) which is notched similarly tothe limbs of the bracket I01, the notches serving as aut matic take-upfor Wear. The hook H0 is in turn connected to the forward end of a pullrod I I2 which extends rearwardly along the feed beam in freely movablerelation.

As shown in Fig. 12, the pull rod I I 2 terminates in a clevis I I3connected to a crank H4 pinned on a shaft I I5 journaled in bearings II6 mounted on the feed beam floor 40. A parallel crank II'I pinned onthe shaft H5 is connected to a power spring II8. Splined 0n the shaft H5is a sliding collar I 20 having an upstanding arm IZI car- 'ryingarollerI22adapted to selectively engage sideizofitheitopvfplatei 33.:otrthelmain booms The-11 carmiwhichewillsbe. engaged-why :thecrolleni I2 2 i is determined by the position of the splinedc'co'llar I 29pwhichis shiftedib'y aalever :I 21 l engagingza' groove "I 28 in thecollar,andimountedrton a-=pivot f The :collar H 20;

is heldiinxselected position. byvaspring pressed; ball I30 engaging.selected notches or drill ipointsx I 3 I in the shaft.

The; central blowpipe unit U'.WhiCh'i'h9.S *beel1 describedwasshown-:in: Fig: 7; is aligned-withthe main-boom T andv is rigidly"secured? to the-1..

I-beam 51 is extended an appropriatedistance 'on n one or both sides zofthe central unitito ssupport.

such additional units: In thesezaddition'al:units:J the frame *isclosed": by "a backing *platet'l SI instead of the plate 65 for thecentral-unit.-

To adjust the-additional"blowpipe :units with. respect-to; the centerunit for'the purpose of. determining; the length of stocktbetween-cuts arack I;322 -is securediunde'r the :upperflange of: theI-loeam 67, andmesheswith-vat pinion I33 on a. shaft :I 34 journaled in a'boss on the"plate I3I and operated by ahandle I353 Whenlthis of the Iebeam 6T.Tofacilitate.the settingio'f the additional units, as shown in-Fi"g.::6,' a scale I-38- may-:be provided on the .Lbeam 6'! cooperatingwith a pointer I39 ontthe: um't,='- for eX--.

ampieon the plate I3I.

The additional blowpipe units are'adapted'for 2 the retractionor'raisingofthe blowpipes thereof:

simultaneously with the central .unitflby. extend-1 ing the cam surface95 on the rockeryarm 95'.

laterally so that it engagesath'e trailing arm: crank roller '92 Y ofthese additional units. These ad;

ditional 'units .areadapted for tilting 1.0f their.

blowpipessimultaneously with the'central unit,

by extending the rod I 08 laterally vto'engage slotted members MI!:secured. to the respectiveblowpipe holders BI of the additional units;The

elongatedrslots'of the membersdllll perrnit the trailing arms J 0f theadditional units over cocked billetsi- By valving off the center unitand using I only the two outboard units, the maximum length be-.

tween cutsmay be obtained for one machine, or

two or more machines'will allow. .four. or more simultaneous cuts to bemade. Obviously. an infinitenumber. of'variations are possiblelusingi,

'to' ride combinations of aplurality'otnnits andla plu;

rality of machines.

In setting up the vmachine. for operation, it;. will be assumed that thebaseK has beenproperly-i positioned with respect toi-the-conveyortable-R andthat .the stock A to becut 'hasbeen properly.

" the=action.of' thepower spring I I8, and puns positioned thereonw Thepin' 21 is removed-from the socket-26 to release the link- L, and thegas on .theiparticularshape of stock :A won-the co veyortableR; It isalsorassumedtthat th'e ltra pressures are adjusted forthe.cuttingpperation Q i 'cut;:.the i hook I I I] "is positioned: in;engagement .the cylinder the upper farther c'ornen f this't'obk, w up aeto drive fthefeed beam at 'the cutting sped it suit the materialltobevouti When .round "stock is to be cutrthe lpro lons forwtiltingr-theblowpipe may not be 'neces'sary and' i'i de'sired the :hook1I Ill-may bedisconnecte fromxth'e rodi. I.08; and' rest=idlyion th'e 'feed beamfloor .1 40,? ialthoug-h the machine? will; functio perfectly with. thetilting 'provision' in use. -;.--Bi'1 when stock of. :polygonal tcross\sectionm-is; to the withif the 'rodyl 08, and the lever;l=211'is-roperate to shift the :rolleriarm-ecollar'r'l 201 130selectfi'ath cam: I23, ZI 24,1125 or" I 26 :suitable 'ifor-fthe' particular size of stocks.

In operation,the largeefluid mpressure cylinder P is actuated; causing"the :pis'tonr-rod "I-I 'toF-s-re tract and": the .levers- Ltcausei the:main boom and all parts rtherleonwto 7 swing ii forward zzan downwarduntil stopped :by the stop-i'ibracketi of the main boom '1' engaging thetop of it stock Preferably the cylinders'P isactuate'd by the operatordepressing :apushebuttonz which :ii energizes the :solenoid :2.I tooperate theizwalve e 20 and consequently admits compresse'damrrztoar.

After the' stop: --bracketw36 'is" brought to rest rz on the topjoftherstock; thecylinde'n lllfi isaactu ated'to releasethe pusher -rod :I02,?whichi'permits. the rock shaft 96 to swingrearwardly;czcarryingithe" cam surface =-with-it. =This..-:permitsrthe: roller .-.9 I- to thetrailing arm cranka 92 tor-move rearwardly and 1 permit the trailingiarm -zl -.to :de-.' .4 scend. and contactthe surface of the 'stoc-lti'The drive-motor M" is then started,- preferably. by the operatordepressing another push button which simultaneously startsy-the drivemotor i the forward. direction andv :bymeans of::silitableelectricallyoperated valves turns on :all preheat and cutting; gases.The motor: M-wthro-ughrree .duction gearing-V drives theisprocket'56Rwhich by means of thechain- 55- drives the sprocket-5.4; r Throughthe shear'pin '53 thesprocket 54: drivesthe flange 52 and itsshaftlswandthepinion'wfl thereon, which meshing with the mack-KW drives 45 $1161feed :beamv D forward, guided f by; the rollerssyi 45 and 46 withinthemain boom T.

Upon forward movement of the carriage one: feed beam .Dwhen. polygonalstock -is being out: duringthe initial portion of the .-cuttingrstroke:;:i=i the forward. poition. l8-which .is curved downwardly andrearwardly: first engages the 'upper and nearer corner of .the-stockandas the-trail;- ing arm 4 J moves forward, the .:-surfaoe 'IBwri-desalong this corner until. the skidportionfIS passes overthe corner ontothe mama-portion .oizxthe surface of the stock. At thebegin'ningeotizthis stroke; the power spring: IIB hOldSxtheilOd I02 forward so that.the transverse :rod .1 I] 8 holds-the blowpipes B rearwardlyj;inclinedwThusfztheszcut is started with the blowpipe positionednin t'he-is;

trailing angle shown in-Fig-. :7.

Duringa'the main portion of the-:cuttin'gsstmke, the skid .I 9" rides"over 1 therzmaj or portioniofsthe surface; of the stock-Meantime-.theerollep I22 having engagedone "ofwthe; camsi 1239424; .125ill or I26; pushesthearm- I2I irearwardly against the "rod l I2rearwardly, which through h'ook I l0 rod-I68 and-bracket' l lilgradually* tilts the blow- .pipe; B about I the pivot '11, 'during' this"inter mediate part of the forward-movement *of the feed beam D." Afterv.the intermediate-or mason portibn of the cuttingf:str'okeputhe skid"I9 "rides" downoe.

during the final portion of the cutting stroke, the skid 19 descends andthe upwardly curved rear portion 80 rides down this far corner of thestock. By this time the cam I23, I24, I25 or I26 has completed itsaction so that the blowpipe has now reached the leading angle, and thisleading angle is maintained until the cutting oxygen jet has passedthrough the final triangular portion of the stock and has completed thecut.

After the cut is completed, the operator presses a push button whichstops the motor M. However, if the operator should fail or unduly delayto press the button, and over-travel of the feed beam takes place, thelimit switch 58 is tripped by the cam carried by the feed beam, andstops the motor M when the feed beam reaches its fully extendedposition. At the same time upon completion of the cutting stroke, fluidunder pressure, preferably compressed air, is admitted to the cylinderHi6, which pushes on the rod I02 in engagement with the roller I androcks the shaft 9?, causing the cam surface 95 engaging the roller 94 totilt the crank 92, thus raising the trailing arm J and the blowpipe andpreheat tips carried thereby, clear of the stock for the returnmovement. Preferably a single push button is provided, which in additionto actuating the cylinder I96, alsocauses the shutting off of all gases,stops and reverses the drive motor M at a predetermined speed higherthan the cutting speed, and reverses the direction of flow of air to thelarge operating cylinder P. When the feed beam reaches its fullyretracted position,

' the limit switch 59 stops the motor M.

This invention is not to be limited to the precise details disclosed,but instead the invention is to be construed to embrace such embodimentsof the broad ideas as fall within the scope of the appended claims.

What is claimed is:

1. Blowpipe apparatus comprising, in combination, a carriage adapted tobe propelled in a forward direction during an operation'on aworkpiece; ablowpipe-supporting arm pivotally con-s.

nected to said carriage and extending in a rearward direction from suchpivotal connection, said arm having an end portion freely movablevertically and adapted to bear against successive surface portions ofthe workpiece as said carriage, is propelled in such forward direction;and a blowpipe between said carriage and said pivotal connection andsecured to said arm adjacent such freely-movable end portion, wherebysaid arm maintains the gas jet discharge orifice means of the blowpipeat a substantially constant distance from the surface of the workpieceduring such operation.

2. Blowpipe apparatus comprising, in combination, a carriage adapted tobe propelled in a forward direction during an operation on a workpiece;a blowpipe-supporting arm pivotally connected to said carriage andextending in a rearward direction from such pivotal connection, said armhaving an end portion freely movable Vere tically and adapted to bearagainst successive surface portions of the workpiece as said carriage ispropelled in such forward direction; and a blowpipe secured to said armadjacent such freely movable end portion, whereby said arm maintains thegas jet discharge orifice means of the blowpipe at a substantiallyconstant distance from the surface of the workpiece during suchoperation, in combination with mechanism operable to progressively varythe inclination of said blowpipe from a trailing angle to a leadingangle relatively to said surface during free vertical and forwardmovements of said end portion of the blowpipe-supporting arm. I

3. Blowpipe apparatus for thermochemically cutting elongated stock suchas solid steel bars of round and rectangular cross section, suchapparatus comprising a carriage having an extension adapted to overhangsaid stock during a cutting operation thereon; propelling means adaptedto advance said carriage in a forward direction toward said-stock tomove said extension transversely of and above said stock; ablowpipe-supporting arm pivotally connected to said extension andextending rearwardly and downwardly from such pivotal connection, saidarm having an end portion freely movable vertically and adapted to bearagainst successive surface portions of the stock as said carriage ispropelled in such forward direction toward said stock; and a cuttingblowpipe disposed between said carriage and said pivotal connectionandsecured to said arm adjacent such freely-movable end portion, theconstruction and arrangement being such that said arm maintains the gasjet discharge orifice means of said blowpipe at a substantially constantdistance from the surface of the stock during the cutting operation.

4. Blowpipe apparatus for thermochemically cutting elongated metal stocksuch as solid steel bars of round and rectangular cross-section, suchapparatus comprising a carriage having an extension adapted to overhangsaid stock during a cutting operation thereon; propelling means adaptedto advance said carriage in a forward direction toward said stock tomove said extension transversely of and above said stock; ablowpipe-supporting arm pivotally connected to said extension andextending in a rearward direction from such pivotal connection, said armhaving an end portion freely movable vertically and adapted to bearagainst successive surfaceportions of the stock as said carriage ispropelled the gas jet discharge orifice means of said blowpipe at asubstantially constant distance from the 7 surface of the stock duringthe cutting operation,

and mechanism for progressively varying the angular position of saidblowpipe during free vertical and forward movements of said end portionof the blowpipe-supporting arm, to discharge the oxygen cutting jetrearwardly at the beginning and forwardly at the completion of thecutting operation.

5. Blowpipe apparatus as claimed in claim 3, wherein said carriage isreciprocable, said propelling means also is adapted to retract saidcarriage in a direction away from the stock and to its initial positionupon completion of the cutting operation, and said apparatus includesmechanism for lifting the freely-movable end portion of said arm and theblowpipe secured thereto relative to said carriage extension and aboutthe pivotal connection of said arm. thereto, to maintain said endportion and blowpipe both clear of said stock during such retraction ofsaid carriage. 1

6. Blowpipe apparatus comprising, in combination, a carriage adapted tobe propelled as a forward stroke for an operation upon a workpiece; ablowpipe supporting arm pivotally connected to said carriage andextending in a rearward di- 3 rection from suchpivota-l connect ion;-,and a blowl. pipe carried by the rearward, portiOnof said-arm andlocated between saidicarriagerand,said; -pivotal connection; said:armrhayingse front cam Blowpipe' ,iapparatus- ;comprisin in com---bination, a:-carr iage adaptedito be -propelled as a forward strokefor; an, operation -on-a1-workpi.ece; a blowpipesupporting:armpivotallyconnected -to said-carriageand extending in 'arearward direction; fromsuchpivotalrconneotion; and a-blow-pipe carriedby said arm-anddocated between said ear- 4 riage and saidpivotal;connection-, said-armuhaving-a front portion of; itstunderisurfacecurved downwardly to engage and beartzagainstsucces- -,sive portions of"the; surface, ofthe workpiece and ride run-said surface-assaid-"carriage; moves for- -ward:during,-, the initial portion of :itsstroke and thereby, raise said blow-pipe, saidv under surface having a:downward proj'ectionat,- the :end of said downwardlyv curved vportionadapted to ride gonto r the surface :of-saidstock as i said-stock:leavessaid downwardly curved portion-andmontinue ineen- ,7gag-ementwith successive portions of said: surface during: the major.portion, ofsaid forward stroke tomaintain thev nozzle of. saidzblowpipeat asubstantially constantdistance fromnthe: surface. of

the workpiece.

.8. Blowpipe apparatus comprising, ,in combination, a carriage-adaptedto berpropelled as a forward stroke: for: an operation; upon, avworkpiece; ablowpipe. supporting armzpivotally connected .to

- said vcarriage sand extending I rearwardly .,there- 1: from; andablowpipercarried by the rearward portion of, said arm and-locatedbetween said carriageand such pivotal-connection;saidarm having.- askidportion adapted to; bear against successive surf ace portions :ofsaid workpiece ,as said" .vcarriageeis propelled rinsuchforwardfldirection to maintain the blowpipe nozzle .at a: substantiallyA constantdistance .fromc the workpiece surf ace;

saidvarm having a; rear: cam portion .of its. ,under surface. curved;upwardly. and rearwardlywtoien-.-- gage successive portions of the.workpiecesurface and ride down the same during the finatiportion of saidA forward :stroke to slower .l the blowpipe .nozzle closer .to l theworkpiece.

. Blowpipe apparatus comprising, in. comhi :nation a-carriage. adapted.to be ,propelledin a forward directionduring an operation onanworkpiece, a zblowpipe supporting .arml pivotal ly. connected ito thefront end of ,said carriage; and extending .rearwardly .therefromsand,ha-ving Y a a transverse fork; a blowpipe holder. having a transverseyoke; pivoted to said forknandt a blow- .pipe mounted. .in r said..holder and extending through saidiyokecwithiiits nozzle adjacent thepivotal axis of said yoke and fork.

i l0. B lowpipe apparatus; comprising, .inecombination, acarriagevadapted ltonbelpropelledlin 2. forward direction during anoperationona-workpiece ;-,a. b-low-pipe -supporting.-,arm pivotallyconnected to the frontz-end-of said carriage and ex-.

tending rearwardly therefrom and having-ta transverse fork providedwithlugs adaptedztoenage successive portions of the surface of said-workp iece as said. carriage movesforward, to maintain said blowpipenozzle a substantially constant distance from the surface of said work--.piece; a blowpipe holder having a transverse yoke pivoted to saidfork; and a blowpipemounted in said holder and-extending through saidyokeiwith its, nozzlevadjacent the pivotal axis ofsaidyoke and-fork.

' 11..Inib1oWpipe apparatus, a blowpipe-support- 1 -ing varm having atransverse fork,-a blowpipe holder having a transverse yoke pivoted tosaid tending through said yoke with its nozzle adjacent the pivotal axisof said yoke and fork and a fork a blowpipe mounted insald holder andex- I collar :inthe fork of said arm and connectedto :said blowpipe andyokeand provided with preheat gas passages terminating intips directedtoward thesurface of said workpiece in advance of thegas jet dischargefrom-said blowpipe nozzle. 12.. Blowpipe apparatus comprising in combi--nationa feed beam adapted to be propelled in a forward direction-duringan operation on: elonngatedametal stock and in 'a rearward direction fora return stroke; a transversely extending support rigidly mounted on thefront end of said feed beam; .a blowpipe unit mounted onsaid support andadjustable thereon longitudinally ofisaid support and transverselyofsaid beam, said. .unit

comprising a frame, a blowpipe-supporting arm pivoted to the lowerportion ofsaidframe-and extending rearwardly therefrom, .andawblowpipeholder pivotallylcarried by the rear-portion of said arm. g

13.\Blowpipe apparatus .asvclaimedin claim 12, .in combination with atransverse operating-trod connected to said blowpipe holdeiyand meansfor moving said operating rod. longitudinally of said feed beam totiltsaid blowpipe holderaabout its pivotal connection to. said arm.

- lenBlowpipe apparatusasclaimedin claim 12, invcombination with a rockshaft journaled-on .said support and having a transversely; extendingcam surface, a crank on said blowpipesupporting arm and havinglafollower engagingsaidcam surface, and means movablelongitudinallyof saidfeed beam for rocking said cam surface and causing said cranktoraisesaid blowpipe supporting arm and. maintain it clear of. saidstock during said return stroke.

15. In a blowpipe machine for thermochemically operating upon elongatedmetal stock, said machine havinga main boom, and means for supportingsaid. main boom in position extending transversely of said stock, theimprovement which comprises a feed beam extending longitudinally of saidmain boom and slidably carried therebyand .means fornpropellingsaid feedbeam-relative-- to said main boom andlongitudinally-thereof for movementtoward and over said stock, a-blowpipe supports-extending transverselyof the frontend .ofl saidv beam, and-a; blowpipe supporting arm .pivotedonsaid support and extending rearwardly therefrom, and ablowpipe carriedby theurear portion. of said arm whereby) said longitudinal movement ofsaid feedbeam relative to said main .beam,moves said blowpipetransversely of i said stock.

16. Ina blowpipe machine for thermochemically-operating upon elongatedmetal stock,:.-a base adapted to be mounted atone side of said stock,a-=,mainboom,- and means carried by. said main boom-r-extending-oversaid stock for: supporting a blowpipe and movable relative to said boomfor propelling said blowpipe transversely of said stock, the improvementwhich comprises front and rear links having their lower ends pivoted onsaid base, said main boom adapted to extend transversely to said stockand having front and rear portions pivoted respectively on the upperends of said links, whereby said main boom is mounted for substantiallyparallel movement with respect to said base and transversely of saidstock, whereby said means may be moved with said boom on said links froman inoperative position away from said stock to an operative positiontoward said stock.

Blowpipe apparatus for thermochemically cutting elongated metalstools-such apparatus comprising, in combination, a support movabletoward and away from said stock; a carriage mounted on said support andmovable relatively thereto toward and away from said stock; ablowpipe-supporting arm pivotally connected to said carri'age andextending from such pivotal connection in a direction opposite to thedirection of movement of said carriage toward said stock, said armhaving an end portion freely movable vertically and adapted to bearagainst successive surface portions of the stock during a cuttingoperation; a cutting blowpipe secured to said arm adjacent such freelymovable end portion; mechanism for moving both said support and saidcarriage toward and away from said stock and operable to move suchfreely movable end portion of said arm to bear against said stock andposition said blowpipe to start the cutting operation; and means forpropelling said carriage relatively to said support and toward saidstock to move said arm and said blowpipe across the stock to cut thelatter.

18. Blowpipe apparatus for thermochemically cutting elongated metalstock, such apparatus comprising, in combination, a support or boomswingable toward and away from said stock; a carriage mounted on saidsupport and movable relatively thereto toward and away from said stock;a blowpipe-supporting arm pivotally connected to said carriage andextending from such pivotal connection in a direction opposite to thedirection of movement of said carriage toward said stock, said armhaving an end portion freely movable vertically and adapted to bearagainst successive surface portions of the stock during a cuttingoperation; a cutting blowpipe secured to said arm adjacent such freelymovable end portion; mechanism for rapidly swinging both said supportand said carriage toward and away from said stock to and from a positionto start the cut and operable to move such freely movable end portion ofsaid arm to bear against said stock and position said blowpipe to startthe cutting operation; and means operable after said rapidly swingingmovement for propelling said carriage relatively to said support andtoward said stock to move said arm and said blowpipe across the stock toadvance the blowpipe for cutting the stock.

19. Blowpipe apparatus for thermoch'emically cutting elongated metalstock. such apparatus comprising, in combination, a support movabletoward and away from said stock; a carriage mounted on said support andmovable relatively thereto toward and away from said stock; ablowpipe-supporting arm pivotally connected to said carriage andextending from such pivotal connection in a direction opposite to thedirection of movement of said carriage toward said stock,

said arm having. an end portion freely movable vertically and adapted tobear against successive surface portions of the stock during a cuttingoperation; a cutting blowpipe secured to said arm adjacent such freelymovable end portion; and mechanism for moving both said support and saidcarriage toward and away from said stock and including means operable tomove such freely movable end portion of said arm into position to bearagainst said stock and position said blowpipe tostart the cuttingoperation, and means for propelling said carriage relatively to saidsupport and toward said stock to move said arm and said blowpipe acrossthe stock to cut the latter; said mechanism being operable after thecompletion of the cutting stroke for lifting said end portion andthereby lifting the blowpipe clear of the stock for the return stroke,retracting said carriage to return said arm and blowpipe to startingposition, and then retracting both said support and carriage to movesaid carriage, arm and blowpipe away from the stock.

20. Blowpipe apparatus for thermochemically cutting elongated metalstock of polygonal cross section, comprising in combination, a carriageadapted to be propelled in a forward direction durin an operation onsaid stock, a blowpipesupporting arm pivotally connected to saidcarriage and extending in a rearward direction from such pivotalconnection, said arm having an end portion freely movable vertically andprovided with a work-engaging undersurface, successive portions of suchwork-engaging surface being adapted to bear against a corner of saidstock 7 as said carriage is propelled in such forward direction, and ablowpipe secured to said arm adjacent such freely movable end portion,whereby said arm maintains the gas jet discharge orifice means of theblowpipe at a substantially constant distance from the surface of saidstock durtion thereon, propelling means adapted to ad- Vance saidcarriage in a forward direction to move said extension transversely ofand above said stock, a blowpipe-supporting arm pivotally connected tosaid extension and extending in a rearward direction from such pivotalconnection, said arm having an end portion freely movable vertically andprovided with a work-engaging undersurface successive portions of whichare adapted to bear against successive surface portions of the stock assaid carriage is propelled in such forward direction, and a cuttingblowpipe pivoted to said arm adjacent such freely movable end portionwhereby said arm maintains the gas jet discharge orifice means of saidblowpipe at a substantially constant distance from the surface of thestock during the cutting operation, and means cooperating with saidblowpipe above its pivot to control the angle thereof to start the cutwith the blowpipe held at a trailing angle and to complete the cut withthe blowpipe held at a leading angle.

22. Blowpipe apparatus for thermochemically cutting stock such as solidsteel bars of round and rectangular cross-section, such apparatuscomprising. a 1 reciprocable" carriage @ha'ving tan extension adapted"to overhang said stock during a :cuttingioperation, propell'ing' meansadapted to advance said. carriagezin a'forWard: direction to move saidextension transversely of .and above said stock, a blowpipe supportingarm pivotally connected to said extension and extending in'a rearwarddirection from such pivotal connection,

said, arm having anend'portion freely moving ward direction, and acutting. blowpipe 1 secured to said arm adjacent such freely movable endportion, the construction and arrangement being such" that said armmaintains the 'gas'yjet discharge orifice means of said'blowpipe at 'asubstantially constant distance from the surface of the stock during thecutting operation, said propelling means being-also adapted to retractsaid carriage to its initial position-upon the completion of the cuttinoperation, and said apparatus -REFERENCES CITED The followingreferencesiareof record irigthe file of this'patent:

UNITED STATES PATENTS Number Name "Date 1,858,078 Douglass et a1 Mayi10,1932 1,885,107 Brown N'ov'. 1, 1932 2,143,969 Biggert, Jr. 1 Jan.17,1939 2,259,956 Jones -L-Oct; 2191941 2,283,346 I Bucknam et' a1 May19,1942

' 2,289,786 Jones *July*14,*1'942 2,289,968 Jones Ju1y"14,'*1'9422,297,343 Young 'Sept.*29,?1942 2,365,235 Younget a1 '-Dec. 19,' 19442,365,276 Miller Dec. 19,1944

